Depressed wet bulb water cooler

Abstract

A depressed wet bulb water cooler utilizing an indirect evaporating film heat exchanger having walls defining wet and dry sides. In a particular embodiment, the wet and dry sides are formed respectively as the opposite inner and outer surfaces of elongated hollow tubular conduits. Water from a load is applied across the inner wet side surfaces while intake air is drawn across the outer, dry side surfaces so as to cool the intake air to a first temperature. The cooled air is then flowed as working air at substantially the first temperature over the wet side of the conduits, and discharged.

What is claimed is: 
     
       1. A depressed wet bulb water cooler, comprising: walls formed as an array of elongated, vertically directed conduits having exposed inner and outer surfaces defining respectively an evaporative cooling wet side for latent cooling of air and a dry side for sensible cooling of air;   water discharge means for applying discharge water to the upper inner surfaces of said conduits;   means for flowing air into thermal conductive contact entirely across said dry side surface to cool said air to a first temperature, and then flowing all of said cooled air at substantially said first temperature over said wet side surface whereby to evaporate portions of water on said wet side surface to thereby moisten said air, cool said water and cool said wet and dry side surfaces;   top and bottom headers on opposite sides of said conduit array, isolating the spaces between said conduits from air delivered for flow through said conduits;   means for recovering cooled water from said wet side surfaces; and   means for discharging said moistened air.   
     
     
       2. The cooler of claim 1 wherein said walls define said wet and dry sides as opposite sides of said wall. 
     
     
       3. The cooler of claim 2 wherein said walls are formed as an array of spaced, hollow, elongated conduits defined by said wet and dry side surfaces as inner and outer surfaces, respectively, the flow cross section extending between the surfaces comprising the dry side being substantially uniform. 
     
     
       4. The cooler of claim 2 wherein said walls are formed as an array of elongated, vertically directed conduits and said water discharge means is formed to apply water to the upper inner surfaces of said conduits, said water flowing down the inner surfaces of said conduits to wet said surfaces. 
     
     
       5. The cooler of claim 4 in which said air flowing means comprises means for directing the flow of said air countercurrently to flow of said water. 
     
     
       6. The cooler of claim 4 including top and bottom headers on opposite sides of said conduit array, isolating the spaces between said conduits from air delivered for flow through said conduits. 
     
     
       7. The cooler of claim 6 wherein said discharge means comprises means for distributing said water onto said top header for flow into said conduits to wet said inner surfaces whereby to provide an extended film thereon to enhance the effects of evaporation. 
     
     
       8. The cooler of claim 1 in which said water recovering means comprises storage means for said cooled water. 
     
     
       9. The cooler of claim 8 including means for selectively transferring stored cooled water to said water discharge means whereby to further cool said discharge water. 
     
     
       10. The cooler of claim 8 including means for adding uncooled water to the cooled water in said storage means until said storage means contains a predetermined amount of water. 
     
     
       11. A depressed wet bulb water cooler, comprising: walls having exposed surfaces defining respectively an evaporative cooling wet side for latent cooling of air and a dry side for sensible cooling of air;   water discharge means for applying discharge water across said wet side surface;   means for flowing air into thermal conductive contact entirely across said dry side surface to cool said air to a first temperature, and then flowing all of said cooled air at substantially said first temperature over said wet side surface whereby to evaporate portions of water on said wet side surface to thereby moisten said air, cool said water and cool said wet and dry side surfaces;   means for recovering cooled water from said wet side surfaces;   means for discharging said moistened air;   a secondary heat exchanger having interconnected elongated conduits with an input port and an output port;   means for supplying water to said input port;   means for connecting said output port with said water discharge means; and   means for directing said moistened discharged air around said interconnected conduits whereby to precool water supplied to said wet side surface and to recover some of the water carried in said discharged air whereby to remove heat from the water prior to it being discharged.   
     
     
       12. A depressed wet bulb water cooler, comprising: a housing;   heat exchange walls formed as an array of elongated, vertically directed conduits within said housing having exposed inner and outer surfaces defining respectively wet and dry sides;   water discharge means within said housing for applying water to the upper inner surfaces of said conduits whereby to provide an extended film of water on the inner surfaces of said conduits;   means entirely within said housing for flowing air into thermal conductive contact entirely across said dry side surface, and then flowing all of said air over said wet side surface to thereby moisten said air, cool said water and cool said wet and dry side surfaces;   top and bottom headers on opposite sides of said conduit array, isolating the spaces between said conduits from air delivered for flow through said conduits;   means for recovering cooled water from said wet side surface; and   means for discharging said moistened air.   
     
     
       13. A method for cooling water, comprising: discharging water across the wet side of a heat exchanger having heat exchange walls formed as an array of elongated, vertically directed conduits with exposed inner and outer surfaces defining respectively wet and dry sides;   flowing air entirely across said dry side surface to cool said air to a first temperature and then flowing all of said cooled air at substantially said first temperature over said wet side surface whereby to evaporate portions of said water on said wet side surface to thereby moisten said air, extract heat from said water and cool said first and second exposed surfaces;   recovering cooled water from said wet side surface; and   discharging said moistened air.   
     
     
       14. The method of claim 13 in which said water is discharged for flow vertically downwardly along said heat exchanger wet side surface. 
     
     
       15. The method of claim 14 in which said air is flowed countercurrently to the flow of said water. 
     
     
       16. The method of claim 13 including the step of storing said cooled water and selectively discharging a portion of said stored cooled water across said wet side surface until the stored water reaches a substantially reduced temperature. 
     
     
       17. A method for cooling water, comprising: discharging water across the wet side of a heat exchanger having opposite exposed surfaces defining wet and dry sides;   flowing air entirely across said dry side surface to cool said air to a first temperature and then flowing all of said cooled air at substantially said first temperature over said wet side surface whereby to evaporate portions of said water on said wet side surface to thereby moisten said air, extract heat from said water and cool said first and second exposed surfaces;   recovering cooled water from said wet side surface;   discharging said moistened air;   passing water to be cooled through a secondary heat exchanger;   using said cooled water which has been passed through the secondary heat exchanger for discharging across said wet side surface; and   flowing said moistened discharged air through said secondary heat exchanger whereby to cool water in said secondary heat exchanger and recover some of the water content of said discharged air.